Hello. I really hope someone can help me. I am 23 and I have now missed two periods. I have taken 2 pregnancy test about 25 days apart and they both come up negative. I have two children and I do not feel pregnant. My youngest is 6 months old. I was sick with both of them and extremely tired, but I don't feel that way right now. My fiancé had a vasectomy 6 months ago, so I am REALLY hoping that I am not pregnant. Please help!

Thanks.

If you normally are very regular, you might want to see your doctor as there are a number of reasons you might be skipping periods all of a sudden. Pregnancy would still need to be ruled out, most likely with a blood test at this point, as that would be the most obvious of reasons. Are you breastfeeding, or did you with your youngest? Have your periods become regular again? It may be simply that they are still regulating even if you have had a few already.
Do you know if your fiancé had several samples checked after his vasectomy? Some people only have one checked, but there really should be a few over a period before you get the all clear... even then, depending on how the procedure was done, some methods do have a greater chance of regrowth... not common, but it happens.